The present invention relates to a method for removing oligosaccharides from animal feed prior to consumption by an animal subject and the resultant animal feed. More particularly, the present invention relates to increasing the metabolizable energy available in the feed, which includes breaking down raffinose and stachyose.
Ground soybeans, corn, wheat, and other similar products are the primary sources of food in the diet of a variety of animals, including hogs and chickens. In particular, soybeans comprise a substantial portion of the diet of these animals. The ground soybean meal contains substantial amounts of the oligosaccharides, in particular raffinose and stachyose. The presence of oligosaccharides is undesired for a number of reasons. Oligosaccharides reduce the metabolizable energy value of the feed given to animals by greater than 15 percent, so that the energy available to the animal is reduced and the animal does not as readily use available energy found in the feed. In turn, non-utilization of available energy will prevent maximum growth and weight gain by the animals who consume the feed. Resultingly, it is desired to increase the amount of energy that can be metabolized by an animal from a food source.
Further problems associated with the presence of oligosaccharides relate to sticky fecal droppings and an increase in flatulence. Oligosaccharides in feed cause the fecal droppings to be stickier than droppings of animals that have not consumed oligosaccharides as part of their diet. Increased flatulence in animals also increases as a result of oligosaccharide consumption. Such problems are exacerbated in farms and production facilities where animals are concentrated, as extremely unpleasant odors are associated therewith. Such strong odors can foul the air of areas adjacent to such facilities. More importantly, sticky droppings can be a problem because they will stick to the feet or hoofs of the animals in contact with the droppings. Adherence to the feet of the animals will cause the formation of sores on the animals. The sores can then result in the animals becoming infected, with the sores decreasing the fitness of such animals. As such, there is a strong desire to reduce the stickiness of droppings so as to promote better overall health in a flock or herd of farm animals. It is further desired to reduce the occurrence of flatulence in these animals. For the above reasons, it is desired to have a method and/or composition for removing oligosaccharides from feed.
Previously, attempts have been made to remove oligosaccharides from feed by using enzyme technology to hydrolyze and remove the oligosaccharides. These attempts have failed in part because the methods for promoting hydrolysis typically included heating the enzyme and feed mixture. Heat is often necessary to promote hydrolysis; while the heat results in the hydrolyzation of the oligosaccharides it also causes a maillard reaction. This reaction causes sugars in the feed to caramelize and prevents complex sugars from being readily metabolized by the animals that are fed the treated feed. The resulting maillard reaction reduces the amount of energy available to the animal.
Other methods for removing oligosaccharides have included adding an enzyme to the feed prior to consumption by an animal, but not inducing immediate hydrolyzation. The enzyme hydrolyzes the oligosaccharides in the gut of the animal. This process has failed because it can be impractical and does not sufficiently break down or hydrolyze the oligosaccharides. In particular, there is a risk the enzyme will degrade as a result of storage prior to hydrolyzing the oligosaccharide. Also, when the enzyme and feed are in the gut of the animal, it is possible the enzyme will be digested prior to the enzyme hydrolyzing the oligosaccharides.
Thus, it is desired to have a method and/or composition that hydrolyzes oligosaccharides and, in turn, eliminates sticky droppings and reduces the occurrence of flatulence. It is also desired to have a method and/or composition that substantially eliminates oligosaccharides and increases the amount of available energy to the animal that consumes the treated feed. In order to increase the amount of available energy that can be metabolized by the animal, it is further necessary to have a method that does not result in a maillard or similar type of reaction. Finally, it is desired to have a method that efficiently and consistently hydrolyzes the oligosaccharides.
The present invention relates to a method for removing, or hydrolyzing to monosaccharides, oligosaccharides found in animal feed and the resultant treated animal feed. In particular, the present invention relates to adding an amount of enzyme to an amount of feed prior to consumption by an animal, whereby the enzyme degrades or hydrolyzes the oligosaccharides found in the feed to form an animal feed having fewer oligosaccharides. Such animal feed will have a higher metabolizable energy level and will decrease the rate of sticky droppings and flatulence in animals that consume such feed on a regular basis. Importantly, an animal that consumes such feed will be able to derive a greater amount of energy from the treated feed as compared to an equal amount of untreated feed. Increased energy absorption results in potentially enhanced weight and feed efficiency gain and health in such animals.
The method is initiated by obtaining an amount of feed and, preferably, treating such feed to reduce the particle size. It is desired for the feed to have a particle size smaller than the particle size of the feed in an untreated or seed state. Decreasing the particle size will allow for greater enzymatic activity because of an increased availability of surface area.
An amount of enzyme will be mixed with the feed to cause hydrolysis of the oligosaccharides. Use of an enzyme is preferred; however, any protein that catalyzes a reaction, whereby oligosaccharides are hydrolyzed to monosaccharides, may be used as long as it does not adversely affect the animal""s health and function under ambient conditions or conditions close to ambient. Any enzyme can be selected as long as it degrades the oligosaccharides to monosaccharides, functions at temperatures less than those which cause a maillard reaction, and the resultant feed has a metabolizable energy value of greater than 20% as compared to untreated feeds. Preferably, the enzyme is selected from the group consisting of xylanase, galactosidase, cellulase, and combinations thereof. Any amount of enzyme can be added as long as the available oligosaccharides are sufficiently degraded. In chickens fed soybean meal, this means approximately 45% or more of the available oligosaccharides are degraded. It is also preferred to add water to the enzyme and feed mixture so as to enhance enzyme distribution and contact between the enzyme and the oligosaccharides. Any method for enhancing enzyme distribution, however, can be used.
The resultant feed should have fewer oligosaccharides than untreated feed. Additionally, the feed should have a metabolizable energy value of greater than 20% as compared to untreated feed. The feed will not contain reaction products resulting from a maillard reaction and will be formed prior to consumption by an animal.
The present invention overcomes a number of problems associated with previously disclosed treated and untreated animal feeds. A resultant feed is produced that has a higher metabolizable energy value, that reduces the rate of flatulence and sticky droppings in animals that consume such feed, and that has fewer oligosaccharides present than untreated feeds. Additionally, the present feed can be stored for a period of time. The method is advantageous because not only are the oligosaccharides reduced to monosaccharides, but the method consistently reduces the oligosaccharides so that a consistent result or feed is achieved.
The present invention relates to a method for eliminating oligosaccharides from animal feed and the resulting animal feed. The method includes the steps of mixing a sufficient amount of an enzyme with an amount of feed, with the enzyme hydrolyzing the oligosaccharides found in the feed. The resulting feed will be substantially free of oligosaccharides and will have a higher true metabolizable energy value than feeds which contain greater amounts of oligosaccharides or have maillard reaction products. Stated another way, the animal will absorb more energy from the present treated feed than an untreated feed. The preferred enzyme for use is a galactosidase, which specifically hydrolyzes the oligosaccharides, raffinose and stachyose.
The method is initiated by obtaining an amount of feed which can be selected from the group consisting of soybeans, corn, wheat, sorghum, and any of a variety of other types of feeds which contain oligosaccharides and which are typically consumed by livestock and farm animals. It is most preferred to apply the present method to ground soybean material because soybeans tend to contain significant levels of oligosaccharides and comprise a significant portion of most farm animals"" diets. Soybeans are fed to such animals because it is desired for them to be fed increased amounts of protein. The feed is preferably ground so that a greater feed surface area is exposed to the enzymes that are mixed with the feed. Typically, the grind size is that which is desired for feeding chickens and/or hogs. As a general guide, finer grinds are preferred. At the very least, it is preferred to crack the seed in half to increase the feed surface area exposed to the enzyme.
Once the feed material is obtained in a sufficient quantity and has a desired particle size, it is placed in a device where the feed and enzyme can be mixed, preferably a mixing tank or similar structure. The amount of feed added to the mixing tank, or similar device, is dependent upon the size of the device. Essentially, any amount of feed can be treated.
Added to the feed in the mixing tank will be an amount of enzyme or protein capable of hydrolyzing oligosaccharides under ambient conditions or conditions whereby the mixture is heated to a temperature below that where a maillard reaction occurs. Any of a variety of enzymes can be used as long as the oligosaccharides, specifically raffinose and stachyose, are broken down to monosaccharides, such as fructose, galactose, glucose, and combinations thereof. The enzyme added must cause the degradation of the oligosaccharides to the monosaccharide constituents, which are more easily metabolized. The oligosaccharides should be hydrolyzed by the enzyme under ambient or near ambient conditions. Further, the enzyme selected must have sufficient enzymatic activity to reduce the amount of oligosaccharides and, resultingly reduce the amount of sticky droppings. Ultimately, the enzyme should sufficiently degrade the oligosaccharides in an amount sufficient to increase the total metabolizable energy available in the feed.
The enzyme should remain in contact with the feed for a period of time sufficient to result in hydrolysis of the oligosaccharides. Generally, this is equal to approximately one (1) hour. Lesser times may be used, dependent upon the enzymatic activity.
While a variety of enzymes can be selected for use in the present method, preferred enzymes include galactosidase, xylanase, cellulase, and combinations thereof. The most preferred enzyme for use is galactosidase, especially xcex1-galactosidase. The enzyme should be added in an amount equal to between about 0.1% and 1% by weight of the feed. Greater amounts could be added, but it is hypothesized that an increase in enzyme activity, more particularly the number of oligosaccharide molecules hydrolyzed, would not occur, as this is a sufficient amount of enzyme to hydrolyze the majority of the available oligosaccharide molecules. In order to achieve a sufficient increase in TME, at least 45% of the available oligosaccharides (stachyose and raffinose) must be removed from soybeans. Similar amounts in other feeds should be removed when such amounts are adjusted in view of the amount of oligosaccharides present in soybeans. Stated another way, the metabolizable energy available to an animal should increase by at least 20%. While it is preferred that greater percentages of the oligosaccharides be hydrolyzed, it is believed that this is a sufficient amount to prevent sticky droppings and to raise the total metabolizable energy available in the feed to levels sufficient to result in increased growth and weight gain by subjects that consume such feed.
While the enzyme can be added to the feed in a dry mix form, it is more preferred to add an amount of water to the feed and enzyme mixture. The addition of water will allow the enzyme to more readily disperse and contact the surface of the feed. Consequently, increased contact results in more accessibility of the enzyme to the oligosaccharides. When a dry mix is used, it has been observed that the percentage of oligosaccharides reduced for a particular amount of enzyme is decreased because presumably there is less contact between the enzyme and the oligosaccharides. As such, the water should be added in an amount sufficient to allow for ready dispersion of the enzyme in the feed mixture. It is most preferred if the water is added to the feed in the mixing tank in an amount sufficient to cover the feed. The mist is most preferably sprayed on the feed to cause greatest coverage.
Once the enzyme is added to the feed material, with or without water, the enzyme should remain in contact with the feed for at least one hour so as to ensure sufficient oligosaccharide degradation. Any amount of time, however, may be used, as long as sufficient degradation of the oligosaccharides occurs. After the break down of the oligosaccharides, it may be necessary to separate the water from the feed. The water should be removed if the feed is going to be stored. Water removal can be accomplished by first draining away the excess water, followed by drying the feed. The drying step can involve any of a variety of methods designed to lower the water activity level of the feed to 0.7 or less. Water activities can vary as long as the amount of water available readily inhibits the likelihood of bacterial propagation. The suitable devices and/or methods can vary as long as a maillard reaction does not occur and the total metabolizable energy level of the treated feed is not lowered. Among the suitable devices are air dryers and low heat dryers. It is desired to remove the moisture to lower the weight of the feed and to prevent spoilage.
The treated feed can then be fed to any of a variety of animals, including cows, pigs, chickens, turkeys, goats, fish, and any of a variety of other animals used in food production. It is preferred to feed the treated animal feed to turkeys or chickens because of the prevalence of sticky droppings in such animals, especially those that are raised in large production facilities where significant numbers of animals are kept in close proximity. The animals should be fed the feed daily until such time as the animals are ready to be slaughtered for human consumption.
It is preferred to produce the feed in a production facility so that when the farmer or rancher receives the feed, it is ready to be fed to the animals without any steps or effort required by the farmer or rancher. It is not necessary, however, to prepare the feed in a production facility prior to sale to the farmer. Instead, the feed can be placed in a trough or bin by the farmer, followed by adding water and a packet of the enzyme. The constituents are then mixed and allowed to stand for about one hour. Alternatively, the feed can include the enzyme with the farmer only required to add water. Once sufficient time has passed to allow for a breakdown of the oligosaccharides, the feed can then be made available to the livestock or animals for consumption. Importantly, the feed must be treated prior to consumption by the animal.